Symbol rate and modulation level controlled adaptive modulation system with TDMA/TDD for high bit rate transmission in high delay spread environments

The authors propose a symbol rate and modulation level controlled adaptive modulation system with TDMA/TDD, which controls both the symbol rate and nodulation level according to the channel conditions to achieve wide dynamic range for the modulation parameter control, as well as to improve delay spread immunity. Moreover, the proposed system applies a symbol rate control suitable for adaptive modulation. Computer simulation confirms that the proposed system is very effective for improving the delay spread immunity in high delay spread environments